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Oskar is a lightweight Javascript module for generating on-screen keyboards. It might look like the screenshot below, but that's up to you - it's fully customisable with CSS.

Oskar Screenshot


Hacker, I beseech thee; use browserify. Please. Life's too short for require.js and all the associated fuckery.

Basic Usage

var oskar = require('oskar');

var keyboard = oskar();

That's it!


Oskar's keymap is fully customisable. A keymap is specified as a named set of layers, only one of which is visible at any given time. Any key may specify a transition to a different layer, allowing implementation of any number of alternate layouts. This is useful, for example, for implementing a shift key.

A layer itself is specified as an array of rows, each row being an array of key descriptors. A key descriptor can be either:

  • an object, recognised properties being:
    • cap, string: symbol to display on keyboard
    • value, any type: value to emit when this key is pressed (defaults to the key cap itself)
    • toLayer, string: switch to this layer on key press (for implementing shift etc)
    • className, string: additional class name to be added to this key's DOM element
  • a string, shorthand for {cap: $string}

As a special case, any key specified by a single space ' ' will be automatically augmented with the space class.

Here's the default keymap which supports lower/upper-case letters, digits, and some punctuation:

var keyMap = {
    0: [
        ['1', '2', '3', '4', '5', '6', '7', '8', '9', '0'],
        ['q', 'w', 'e', 'r', 't', 'y', 'u', 'i', 'o', 'p'],
        ['a', 's', 'd', 'f', 'g', 'h', 'j', 'k', 'l'],
        [{cap: '\u21e7', toLayer: 1, className: 'shift'},
            'z', 'x', 'c', 'v', 'b', 'n', 'm', {cap: '\u232b', value: 'backspace'}],
        [' ']
    1: [
        ['!', '@', '£', '$', '%', '^', '&', '*', '(', ')'],
        ['Q', 'W', 'E', 'R', 'T', 'Y', 'U', 'I', 'O', 'P'],
        ['A', 'S', 'D', 'F', 'G', 'H', 'J', 'K', 'L'],
        [{cap: '\u21e7', toLayer: 0, className: 'shift'},
            'Z', 'X', 'C', 'V', 'B', 'N', 'M', {cap: '\u232b', value: 'backspace'}],
        [' ']

And custom keymaps are passed via the options object:

var keyboard = oskar({keyMap: keys});

Handling Events

The configuration option onkeypress is used to supply a function that will be called when the user presses a key on the keyboard. It receives a single argument: the value of the pressed key.

var keyboard = oskar({onkeypress: function(value) {
    console.log("you pressed: " + value);

As a convenience, Oskar provides a sendTo() method which will automatically hook its output up to an input element:

var keyboard = oskar();

The installed handler recognises a couple of special key values:

  • backspace: deletes the last character
  • enter: triggers a user-specified callback - passed as a second parameter to sendTo() - with theinput` element's current value.


Oskar uses a bunch of classes to identify its various elements:

  • .osk: wrapper element
  • .osk-row: each row of keys
  • .osk-row-{n}: nth row of keys (zero-indexed)
  • .osk-key: an individual key
  • .osk-key.$keyClass: keys can be given specific classes; see Customisation, above

Please refer to the styles in example/index.htm to see a bloat-free working example.